Ellison, alongside Rep. Raúl Grijalva (D-Ariz.), has headed the CPC since 2011. He stepped out of that role this week in order to dedicate more attention to his duties as deputy chairman of the Democratic National Committee (DNC), a post he picked up this year after losing a tight race to Chairman Tom Perez, a former Labor secretary.

Pocan, who was CPC vice chairman, now joins Grijalva as a co-chairman.

The liberal group has long viewed its role as a vital check on both the GOP-controlled Congress and the Democratic leaders reaching across the aisle to forge compromises with the Republicans on fiscal bills and other must-pass legislation.

Under President Trump, Pocan said Tuesday, that role is more important than ever. He’s vowing to use his new post to make the CPC “the voice of the resistance” to the new administration.

“All we need to do is take a look at the devastating cuts proposed in the budget President Trump released today to see the clear distinction between progressives and this Administration and Congress,” Pocan said, referring to Trump’s 2018 budget plan, which proposes steep cuts to a long list of domestic programs favored by the Democrats.

“The CPC will fight the fights against bad policies and offer positive alternatives which demonstrate progressives have a pulse on the will of the people and a plan forward.”

First elected in 2012, Pocan is also a co-chairman of the Congressional LGBT Equality Caucus.

He churned headlines earlier this month when he stormed into the neighboring Wisconsin district of Speaker Paul Ryan (R-Wis.) and staged a town hall meeting with Ryan’s constituents to highlight the cuts to healthcare benefits under the Republicans’ proposal to overhaul ObamaCare. That fight, Pocan said, is just beginning.

“House Republicans think they can get away with passing a healthcare bill that will cause 24 million Americans to lose coverage, but the CPC will work with outside groups to ensure people understand what Congress is doing,” he said.